In the related art, Patent Literature 1 discloses a pressure sensor including a sensor section that is provided with a diaphragm and a first gauge resistor to a fourth gauge resistor that are formed on the diaphragm to form a bridge circuit, and outputs a sensor signal based on pressure, and a support member that cantilever-supports the sensor section.
As shown in FIG. 6, in the pressure sensor, a sensor section J10 is formed in a rectangular parallelepiped shape, and has a fixed end J21 on one end thereof in a longitudinal direction thereof, in which the fixed end J21 is bonded to a support member J40 to be cantilever-supported. Further, the sensor section J10 is formed using a silicon substrate J20 having a main surface that is a (001) plane, and a diaphragm J24 is formed in the silicon substrate J20. The longitudinal direction of the sensor section J10 is parallel to a [110] direction.
The diaphragm J24 is formed in a square shape of which the outer contour line has a first side J24a to a fourth side J24d, in which the first side J24a and the third side J24c that face each other are parallel to a [−110] direction, and the second side J24b and the fourth side J24d that face each other are parallel to the [110] direction. Here, the first side J24a is disposed on the side of the fixed end J21. In the diaphragm J24, since central portions of the first side to the fourth side J24a to J24d are easily distorted when pressure is applied, a first gauge resistor to a fourth gauge resistor J25a to J25d of which resistance values are changed when the distortion is applied are respectively formed in portions adjacent to the central portions of the first side to the fourth side J24a to J24d. 
In the pressure sensor, since the sensor section J10 is cantilever-supported by the support member J40, compared with a case where the entirety of a rear surface of the sensor section J10 is bonded to the support member J40, thermal stress generated in the diaphragm J24 when an external temperature is changed can be reduced. That is, the thermal stresses applied to the first gauge resistor to the fourth gauge resistor J25a to J25 can be reduced.
However, in the pressure sensor, when the external temperature is changed, the thermal stresses applied to the first gauge resistor to the fourth gauge resistor J25a to J25d can be reduced, but cannot be removed completely. In this case, a large thermal stress is generated in a portion close to the fixed end J21 in the diaphragm J24, and a thermal stress smaller than that generated on the side of the fixed end J21 is generated in a portion distant from the fixed end J21 in the diaphragm J24.
That is, the large thermal stress is applied to the first gauge resistor J25a, and a small thermal stress is applied to the third gauge resistor J25c. Thus, different thermal stresses are applied to the first gauge resistor to the fourth gauge resistor J25a to J25d when the external temperature is changed, and thus, a sensor signal becomes non-linear with respect to temperature (see FIG. 10). In this case, temperature characteristic correction of the sensor signal can be performed by an external circuit or the like, but if the sensor signal is non-linear with respect to temperature, the temperature characteristic correction becomes complicated.
In the above description, an example in which the pressure sensor that includes the sensor section J10 including the silicon substrate J20 in which the (001) plane is the main surface is described, but for example, even though the pressure sensor is configured to include the sensor section J10 including the silicon substrate J20 in which a (011) plane is the main surface, the above-mentioned problem similarly arises.
Further, since the sensor section J10 is cantilever-supported by the support member J40 in the pressure sensor, compared with a case where the entirety of the rear surface of the sensor section J10 is bonded to the support member J40, the thermal stress generated in the diaphragm J24 when the external temperature is changed can be reduced, and reduction of pressure detection accuracy can be suppressed.
However, in the pressure sensor, when the external temperature is changed, the thermal stress generated in the diaphragm J24 can be reduced, but cannot be removed completely. In this case, a large thermal stress is generated in a portion close to the fixed end J21 in the diaphragm J24, and a thermal stress smaller than that generated on the side of the fixed end J21 is generated in a portion distant from the fixed end J21 in the diaphragm J24. Specifically, the largest thermal stress is generated in a central portion of the first side J24a positioned on the side of the fixed end J21 in the diaphragm J24. Further, in the pressure sensor, the first piezoresistive element J25a is formed adjacent to the central portion of the first side J24a. 
Thus, when the external temperature is changed, different thermal stresses are applied to the first piezoresistive element to the fourth piezoresistive element J25a to J25d, and thus, a difference between the thermal stresses applied to the first piezoresistive element to the fourth piezoresistive element J25a to J25d is output as noise (offset), and the pressure detection accuracy is reduced. Particularly, since the large thermal stress is applied to the first piezoresistive element J25a formed adjacent to the central portion of the first side J24a, a difference between a resistance value change of the first piezoresistive element J25a and resistance value changes of the other second to fourth piezoresistive elements J25b to J25d becomes large.